1. Field of the Invention
This invention relates to the field of hole saws of the type having a cup-shaped cutter, a drive shaft and a centering rod extending within the interior of the cutter along the central axis thereof. A common problem in the use of hole saws is that the material cut by the cutter accummulates and becomes jammed in the interior of the cup-shaped cutter and eventually has to be removed by a cumbersome and time consuming operation.
2. Description of the Prior Art
The hole saws in use today are usually provided with holes in the base or side of the cup-shaped cutter which permit the insertion of a nail, screwdriver or other tool for pushing out the jammed material in the interior of the cutter. However, this unjamming method is not entirely satisfactory. Firstly, the procedure is time consuming and difficult to perform. Secondly, the procedure often results in damage to the drill or hole saw, especially when performed while the hole saw is secured on the drill.